Abstract

Live weight and liveweight gain of dairy heifers has been described in New Zealand and overseas, however, the change in stature and pattern of proximal and distal bone growth has, to date, received little attention. This study describes the proportional changes in stature with live weight, in a cohort of commercial dairy heifers (Holstein-Friesian, Jersey, and Holstein-Friesian-Jersey crossbred) from birth to 15 months of age. Comparisons of height, length, girth, and distal and proximal forelimb length (stature) revealed that at the same live weight, these parameters differed among breeds (P<0.05), however, the magnitude of the differences among breeds was consistently less than 1 cm. As heifer live weight increased, the contribution of the distal limb to increases in height decreased, which is consistent with knowledge that physeal closure in cattle occurs earlier in distal limb bones, such as the metacarpus, than in proximal limb bones, such as the humerus. In addition, the understanding of proximal and distal growth in cattle identifies when heifers are most susceptible to growth checks. Keywords: bone; stature; fracture; dairy heifer

MJ, Gibson, CW Rogers, RE Hickson, KE Dittmer, and PJ Back

New Zealand Journal of Animal Science and Production, Volume 81, Online, 45-50, 2021